A new method of synthesizing hemicellulose-derived porous activated carbon for high-performance supercapacitors

In this work, hemicellulose-derived porous activated carbon materials are synthesized by a new method. The nanoporous carbon is prepared for the first time by one-step chemical activation of hemicellulose. The hemicellulose extracted from pomelo peel is used as precursor, and zinc chloride is used as the activator. The porous activated carbon material with large specific surface area of up to 1361 m(2) g(-1) is fabricated by a one-step chemical activation at a low temperature of 500 degrees C. The roles of the activator/carbon material ratio and activation temperature are studied in detail. Benefiting from the porous structure and favorable activation temperature, the as-prepared carbon material possesses ideal electrochemical capacity. The porous activated carbon material performs an excellent specific capacitance of 302.4 F g(-1) at the current density of 0.5 A g(-1) in 6 M KOH and cycling stability of 98.6% capacitance retention after 10000 cycles. For all-solid symmetric supercapacitor, the energy density is 11.7 W h kg(-1) at the power density of 349.9 W kg(-1). The hemicellulose-derived porous activated carbon material shows unique properties, making it an ideal advanced electrode material for high-performance supercapacitors.